The present disclosure relates generally data communications, and more particularly, to a system and method for providing Short Message Service (SMS) to a wireless mobile terminal operating in a hybrid wireless network.
A typical wireless network is composed of two sub-networks: a Radio Access Network (RAN) which handles radio related issues such as assigning radio resources to a mobile terminal (or “mobile” in short) upon request for services, and a Core Network (CN) which links the mobile user to wireline networks. Current specifications of wireless networks require that the RAN and CN have the same wireless technology in order to provide wireless services. These networks may be referred to as “homogeneous networks.” For instance, a GSM mobile will only operate in a wireless network which its RAN and CN are both GSM wireless technology based. FIG. 1 illustrates a GSM wireless network 100 composed of a GSM RAN 102 and a GSM CN 104.
The GSM RAN 102 includes a GSM Mobile Station (MS) 106 that communicates to a GSM Base Station System (BSS) 108 through a GSM radio channel 110. The GSM BSS 108 includes a GSM Base Transceiver Station (BTS) 110 and GSM Base Station Controller (BSC) 112.
The GSM Core Network (CN) 104 includes a GSM Mobile Switching Center (MSC) 120 that is connected to the GSM BSC 112 as well as a GSM Gateway MSC (GMSC) 122 by using SS7 ISUP communications 124. The GSM GMSC 122 is also connected to the Public Switched Telephone Network (PSTN) 126 by using SS7 ISUP communications 124. In this figure, a telephone 128 is shown to be connected to the PSTN 126 as an illustration of a calling/called party. In addition, a Serving General Packet Radio Service Node (GPRS) (SGSN) 130 is shown to also be connected to the GSM BSC 112. Moreover, a GSM Short Message Service Center (SMS-C) 132, a GSM Home Location Register (HLR) 134 and a GSM Authentication Center (AuC) 136 are all shown to be connected the GSM MSC 120 and the SGSN 130. Further, a GSM Service Control Point (SCP) 138 connects a GSM Billing System 140 to the GSM MSC 120 and the GSM HLR 134. The connection from the GSM Billing System 140 and the GSM MSC 120 utilizes IP. Additionally, a Packet Data Network (PDN) 142 is shown connected to the GSM CN 104 through a Gateway GPRS Node (GGSN) 144 utilizing IP communications.
A disadvantage of the homogeneous network is that, given many wireless technologies that exist today and considering new ones being defined for the future, this is a serious limitation in the wireless service provision to deal with a situation in which a mobile compatible with one wireless technology moves into a wireless network of different technology. This prevents the mobile from getting services and limits the mobile's geographical service area to networks that support a specific wireless technology. The same limitation applies to wireless networks that are CDMA wireless technology based. FIG. 2 illustrates such a CDMA based network 200.
Turning to FIG. 2, a CDMA RAN 201 includes a CDMA MS 202 connected to a CDMA BSS 204 through a CDMA BTS 206. The CDMA BTS 206 is in turn connected to a CDMA BSC 208, which connects to a Packet Control Function (PCF) 210. A CDMA CN 212 connects to the CDMA RAN 201 by the CDMA BSC 208 connecting to a CDMA200 MSC 214. The CDMA MSC 214 is connected to an IS-41 SMS-C 216, an IS-41 HLR 218, an IS-41 AuC 220 and an IS-41 SCP 222. The IS-41 SCP 222 in turn is also connected to the IS-41 HLR 218 and a Store and Forward Service 224, which in turn is connected to an IS-41 Billing System 226. In addition, a Packet Data Serving Node (PDSN) 228 is connected to the PCF 210 of the CDMA RAN 200 and a PDN 230. Moreover, the CDMA MSC 214 connects the CDMA CN 212 to a PSTN 232 and, for illustrative purposes, a phone 234.
A hybrid wireless network is a wireless network composed of a RAN and a CN of different technologies linked. Although hybrid wireless networks have advantages, one difficulty is to enable the mobile terminal in the RAN and certain network entities in the CN to exchange message contents without being obstructed by the differences in the technologies involved (e.g., message encoding and decoding schemes). For instance, consider the short message service (SMS) in a GSM Network. When a GSM handset sends a Mobile Originated (MO) short message to the GSM MSC, the message contains not only the destination address but also the address of the SMS-C or Short Message Service Center. In GSM networks, each GSM subscriber may have different address of the SMS-C because the address of the SMS-C is stored in the GSM subscriber's SIM card. In contrast, a CDMA network typically uses a centralized SMS service centre to deliver short message. Consequently, the CDMA handset sends only the destination address for the MO short message. Thus, in the CDMA protocol between the CDMA handset and the MSC, the service centre address is not communicated.
If a hybrid network system were created where a GSM SIM card could be inserted into the CDMA handset, a MO short message could be sent from the CDMA mobile handset to a hybrid MSC. However, the standard CDMA protocol is still used between the CDMA handset and the Hybrid MSC. Under the standard CDMA protocol the GSM service centre address would not be sent to the Hybrid MSC. What is needed, therefore, is a method and system for providing sending SMS messages from the mobile to a hybrid MSC in a hybrid system and a routing mechanism in the hybrid MSC to route the SMS message to the appropriate SMS-C in the core network.